Disasters is a Spigot/Bukkit plugin that implements several types of Disasters into the game including lightning storms, acid rain, meteor strikes and wildfires. These Disasters make Minecraft somewhat tougher and could be used on survival servers. Most aspects of the plugin are configurable.
More information about the plugin can be found on its SpigotMC page here: https://www.spigotmc.org/resources/disasters-beta.38859/